G'Day Fella's,

Thanks for sharing Mehul.

I just assumed, that the 10.3 mm was the Bore Diameter, not the Groove and Bullet Diameter?
That being the case 10.3 x 0.039375 ("/Inch), = 0.400" Bore Diameter (1 mm = 0.039375"/Inch).
So generally, rifling is around 0.004" (or just over 0.01 mm), each side (x 2, for 0.008"), this would give this a barrel Groove and Bullet Diameter, of 0.408" ish?

The thing that the bloke being interviewed said, was that he started with the .416 Remington Magnum cartridge ......... so who knows?

Either way .......... Everything that is Old, is New Again!

Avagreatweekendeh!
Homer